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Cognizant
Posted: July 23, 2015
Last activity: July 24, 2015
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Doubt in Email Listener
Hi Team,
I am going through the Email listner topic, i have seen the option "Start Up Option" .Please tell me the difference between 1)Node based startup and 2)Host based start up.
Also could please explain the concept of Server, Node, Cluster, Host in detail.
Thanks in advance.
A few years ago the concepts where easier to distinguish but today with virtual machines it is a bit harder. But Server, Node, Host and Cluster is about this:
A host mostly mean a physial comuputer that hosts multiple applications but can often be seen as equivalen to a server. A host can host mutiple nodes
A server is one physical computer or a virtual machine present itself as a computer. A server contais programs shared by many users like a web server or a application server like Tomcat or mail server. Each of these applications litens for things to do on a TCP port.
A node mostly mean a Server, as above, but can be mutiple applicaton (of the same kind) listening on differnt TCP ports. Nodes are mostly part of a cluster.
A Cluster are two or more nodes (or servers) workig toether to serve a huge aount of users.
A server, or node can serve maybe up to 1000 users (depending on appiction) and a cluster can then serve 1000 times numer of nodes users.
So Host Base startup means start on all nodes on that host whereas node based means start only on that node. All Nodes tend to use ONE database server.If some function need to do database maintenance it must run on only one node.